1. Field of the Invention
The present invention relates to an optical element module including an optical element that receives light or emits light, and a method of manufacturing the optical element module.
2. Related Background Art
In recent years, in order to transmit large volumes of information in communication systems and information processing systems, a technology of transmitting an optical signal generated from a light emitting element such as a laser oscillator element via an optical fiber serving as a light waveguide unit, and of receiving an optical signal transmitted via an optical fiber by a light receiving element such as a photodiode, has been indispensable. For that purpose, there has been technology development in order to optically connect a light receiving or emitting element and an optical fiber easily and inexpensively by use of downsized and large-capacity devices, in an optical communication module, an optical interconnection module, an optical measuring module, or the like.
Conventionally, in order to carry out precise positioning of a light receiving or emitting element and an optical fiber, there is adopted a so-called active alignment technique in which transmission and reception of optical signals are actually carried out while changing relative positions between the both, and the positions are set at a maximum intensity of the optical signals. However, such an alignment technique takes time, which reduces the productivity and yield of optical element modules for optically connecting a light receiving or emitting element and an optical fiber. In particular, the problem is significant in the case in which respective optical elements and the optical fibers are aligned to be optically connected to one another in an optical element array in which the plurality of optical elements are arrayed in parallel and the optical fiber array in which a plurality of optical fibers are likewise arrayed in parallel.
Further, as another problem, when an optical fiber is connected so as to be at an angle to a substrate on which an optical element and a semiconductor circuit element electrically connected thereto are disposed, in the case in which it is necessary to closely dispose a plurality of substrates, for example, as in a backplane, the optical fiber becomes a physical obstruction.
For such problems, an optical element module as shown in FIG. 20 is proposed. (A) in FIG. 20 is a side view thereof, and (B) in FIG. 20 is a cross section taken along B-B of FIG. 20(A). An optical element 8′ and a semiconductor circuit element 9′ are mounted on a front surface of a substrate 2′, and those are electrically connected to a metal circuit on the front surface of the substrate 2′ via bumps 52′. A V groove 2B′ is formed at the front surface side of the substrate 2′ likewise, and an optical fiber 7′ is disposed in the V groove 2B′. A mirror surface 2a′ at 45 degrees formed on the front surface side of the substrate likewise is formed in an optical connection path between the optical fiber 7′ and the optical element 8′.
Then, the optical element 8′ is disposed at a predetermined position by connection via bumps 52′ with flip-chip bonding or the like, and the optical fiber 7′ is disposed at a predetermined position by the V groove, which makes it possible to carry out positioning of the light receiving or emitting part of the optical element and the optical fiber without carrying out an active alignment as described above. Further, because the substrate 2′ on which the optical element 8′ and the semiconductor circuit element 9′ are mounted and the optical fiber 7′ are parallel to one another, even when a plurality of the substrates 2′ are closely disposed, the optical fiber 7′ does not interfere with installation in any case.
Then, in Patent Document 1, there is disclosed a method in which crystal anisotropic etching is utilized for forming a V groove or the like in a substrate of an optical element module as described above. Patent Document 1: Japanese Patent Application Laid-Open No. 2005-10766